diff --git a/SRC/zgesvj.f b/SRC/zgesvj.f
index 311ddf541..85765067f 100644
--- a/SRC/zgesvj.f
+++ b/SRC/zgesvj.f
@@ -474,7 +474,7 @@
          RETURN
       ELSE IF( LQUERY ) THEN
          CWORK( 1 ) = LWMIN
-         RWORK( 1 ) = REAL( LRWMIN )
+         RWORK( 1 ) = DBLE( LRWMIN )
          RETURN
       END IF
 *
diff --git a/SRC/zhbevd.f b/SRC/zhbevd.f
index 73248d78c..94747ac3a 100644
--- a/SRC/zhbevd.f
+++ b/SRC/zhbevd.f
@@ -290,7 +290,7 @@
 *
       IF( INFO.EQ.0 ) THEN
          WORK( 1 ) = LWMIN
-         RWORK( 1 ) = REAL( LRWMIN )
+         RWORK( 1 ) = DBLE( LRWMIN )
          IWORK( 1 ) = LIWMIN
 *
          IF( LWORK.LT.LWMIN .AND. .NOT.LQUERY ) THEN
@@ -387,7 +387,7 @@
       END IF
 *
       WORK( 1 ) = LWMIN
-      RWORK( 1 ) = REAL( LRWMIN )
+      RWORK( 1 ) = DBLE( LRWMIN )
       IWORK( 1 ) = LIWMIN
       RETURN
 *
diff --git a/SRC/zhbevd_2stage.f b/SRC/zhbevd_2stage.f
index f7036aedd..eda9cf872 100644
--- a/SRC/zhbevd_2stage.f
+++ b/SRC/zhbevd_2stage.f
@@ -344,7 +344,7 @@
 *
       IF( INFO.EQ.0 ) THEN
          WORK( 1 )  = LWMIN
-         RWORK( 1 ) = REAL( LRWMIN )
+         RWORK( 1 ) = DBLE( LRWMIN )
          IWORK( 1 ) = LIWMIN
 *
          IF( LWORK.LT.LWMIN .AND. .NOT.LQUERY ) THEN
@@ -446,7 +446,7 @@
       END IF
 *
       WORK( 1 )  = LWMIN
-      RWORK( 1 ) = REAL( LRWMIN )
+      RWORK( 1 ) = DBLE( LRWMIN )
       IWORK( 1 ) = LIWMIN
       RETURN
 *
diff --git a/SRC/zhbgvd.f b/SRC/zhbgvd.f
index 6b3279faa..82d62622c 100644
--- a/SRC/zhbgvd.f
+++ b/SRC/zhbgvd.f
@@ -324,7 +324,7 @@
 *
       IF( INFO.EQ.0 ) THEN
          WORK( 1 ) = LWMIN
-         RWORK( 1 ) = REAL( LRWMIN )
+         RWORK( 1 ) = DBLE( LRWMIN )
          IWORK( 1 ) = LIWMIN
 *
          IF( LWORK.LT.LWMIN .AND. .NOT.LQUERY ) THEN
@@ -391,7 +391,7 @@
       END IF
 *
       WORK( 1 ) = LWMIN
-      RWORK( 1 ) = REAL( LRWMIN )
+      RWORK( 1 ) = DBLE( LRWMIN )
       IWORK( 1 ) = LIWMIN
       RETURN
 *
diff --git a/SRC/zheevd.f b/SRC/zheevd.f
index f8f69417e..01ad3b25c 100644
--- a/SRC/zheevd.f
+++ b/SRC/zheevd.f
@@ -284,7 +284,7 @@
             LIOPT = LIWMIN
          END IF
          WORK( 1 ) = LOPT
-         RWORK( 1 ) = REAL( LROPT )
+         RWORK( 1 ) = DBLE( LROPT )
          IWORK( 1 ) = LIOPT
 *
          IF( LWORK.LT.LWMIN .AND. .NOT.LQUERY ) THEN
@@ -380,7 +380,7 @@
       END IF
 *
       WORK( 1 ) = LOPT
-      RWORK( 1 ) = REAL( LROPT )
+      RWORK( 1 ) = DBLE( LROPT )
       IWORK( 1 ) = LIOPT
 *
       RETURN
diff --git a/SRC/zheevd_2stage.f b/SRC/zheevd_2stage.f
index 216109914..b73d7155e 100644
--- a/SRC/zheevd_2stage.f
+++ b/SRC/zheevd_2stage.f
@@ -337,7 +337,7 @@
             END IF
          END IF
          WORK( 1 )  = LWMIN
-         RWORK( 1 ) = REAL( LRWMIN )
+         RWORK( 1 ) = DBLE( LRWMIN )
          IWORK( 1 ) = LIWMIN
 *
          IF( LWORK.LT.LWMIN .AND. .NOT.LQUERY ) THEN
@@ -436,7 +436,7 @@
       END IF
 *
       WORK( 1 )  = LWMIN
-      RWORK( 1 ) = REAL( LRWMIN )
+      RWORK( 1 ) = DBLE( LRWMIN )
       IWORK( 1 ) = LIWMIN
 *
       RETURN
diff --git a/SRC/zheevr.f b/SRC/zheevr.f
index 603424126..038738ec8 100644
--- a/SRC/zheevr.f
+++ b/SRC/zheevr.f
@@ -479,7 +479,7 @@
          NB = MAX( NB, ILAENV( 1, 'ZUNMTR', UPLO, N, -1, -1, -1 ) )
          LWKOPT = MAX( ( NB+1 )*N, LWMIN )
          WORK( 1 )  = LWKOPT
-         RWORK( 1 ) = REAL( LRWMIN )
+         RWORK( 1 ) = DBLE( LRWMIN )
          IWORK( 1 ) = LIWMIN
 *
          IF( LWORK.LT.LWMIN .AND. .NOT.LQUERY ) THEN
@@ -736,7 +736,7 @@
 *     Set WORK(1) to optimal workspace size.
 *
       WORK( 1 )  = LWKOPT
-      RWORK( 1 ) = REAL( LRWMIN )
+      RWORK( 1 ) = DBLE( LRWMIN )
       IWORK( 1 ) = LIWMIN
 *
       RETURN
diff --git a/SRC/zheevr_2stage.f b/SRC/zheevr_2stage.f
index b520f1228..0ba5a2953 100644
--- a/SRC/zheevr_2stage.f
+++ b/SRC/zheevr_2stage.f
@@ -521,7 +521,7 @@
 *
       IF( INFO.EQ.0 ) THEN
          WORK( 1 )  = LWMIN
-         RWORK( 1 ) = REAL( LRWMIN )
+         RWORK( 1 ) = DBLE( LRWMIN )
          IWORK( 1 ) = LIWMIN
 *
          IF( LWORK.LT.LWMIN .AND. .NOT.LQUERY ) THEN
@@ -781,7 +781,7 @@
 *     Set WORK(1) to optimal workspace size.
 *
       WORK( 1 )  = LWMIN
-      RWORK( 1 ) = REAL( LRWMIN )
+      RWORK( 1 ) = DBLE( LRWMIN )
       IWORK( 1 ) = LIWMIN
 *
       RETURN
diff --git a/SRC/zhpevd.f b/SRC/zhpevd.f
index 540469a57..1a033de79 100644
--- a/SRC/zhpevd.f
+++ b/SRC/zhpevd.f
@@ -270,7 +270,7 @@
             END IF
          END IF
          WORK( 1 ) = LWMIN
-         RWORK( 1 ) = REAL( LRWMIN )
+         RWORK( 1 ) = DBLE( LRWMIN )
          IWORK( 1 ) = LIWMIN
 *
          IF( LWORK.LT.LWMIN .AND. .NOT.LQUERY ) THEN
@@ -363,7 +363,7 @@
       END IF
 *
       WORK( 1 ) = LWMIN
-      RWORK( 1 ) = REAL( LRWMIN )
+      RWORK( 1 ) = DBLE( LRWMIN )
       IWORK( 1 ) = LIWMIN
       RETURN
 *
diff --git a/SRC/zstedc.f b/SRC/zstedc.f
index 16d90a216..4a5d9fa69 100644
--- a/SRC/zstedc.f
+++ b/SRC/zstedc.f
@@ -296,7 +296,7 @@
             LIWMIN = 3 + 5*N
          END IF
          WORK( 1 ) = LWMIN
-         RWORK( 1 ) = REAL( LRWMIN )
+         RWORK( 1 ) = DBLE( LRWMIN )
          IWORK( 1 ) = LIWMIN
 *
          IF( LWORK.LT.LWMIN .AND. .NOT.LQUERY ) THEN
@@ -472,7 +472,7 @@
 *
    70 CONTINUE
       WORK( 1 ) = LWMIN
-      RWORK( 1 ) = REAL( LRWMIN )
+      RWORK( 1 ) = DBLE( LRWMIN )
       IWORK( 1 ) = LIWMIN
 *
       RETURN
diff --git a/TESTING/CMakeLists.txt b/TESTING/CMakeLists.txt
index f9c2482fc..58164e516 100644
--- a/TESTING/CMakeLists.txt
+++ b/TESTING/CMakeLists.txt
@@ -177,6 +177,9 @@ add_lapack_test(zlse.out lse.in xeigtstz)
 #
 # ======== COMPLEX16 DMD EIG TESTS ===========================
 add_lapack_test(zdmd.out zdmd.in xdmdeigtstz)
+#
+# ======== COMPLEX16 WORKSPACE QUERY PRECISION TEST ===========
+add_test(NAME LAPACK-test_wq_zrwork COMMAND $<TARGET_FILE:test_wq_zrwork>)
 endif()
 
 
diff --git a/TESTING/EIG/CMakeLists.txt b/TESTING/EIG/CMakeLists.txt
index d99762d43..66ead8798 100644
--- a/TESTING/EIG/CMakeLists.txt
+++ b/TESTING/EIG/CMakeLists.txt
@@ -128,4 +128,5 @@ endif()
 if(BUILD_COMPLEX16)
 add_eig_executable(xeigtstz ${ZEIGTST} ${DZIGTST} ${AEIGTST})
 add_eig_executable(xdmdeigtstz ${ZDMDEIGTST})
+add_eig_executable(test_wq_zrwork test_wq_rwork.f)
 endif()
diff --git a/TESTING/EIG/test_wq_rwork.f b/TESTING/EIG/test_wq_rwork.f
new file mode 100644
index 000000000..efaa0701e
--- /dev/null
+++ b/TESTING/EIG/test_wq_rwork.f
@@ -0,0 +1,182 @@
+*> \brief Test workspace query precision for z* RWORK
+*
+*  =========== DOCUMENTATION ===========
+*
+*  Purpose
+*  =======
+*
+*  TEST_WQ_RWORK validates that workspace query calls (LWORK=-1,
+*  LRWORK=-1, LIWORK=-1) return exact RWORK sizes for COMPLEX*16
+*  routines with O(N^2) LRWMIN formulas.
+*
+*  When LRWMIN > 2^24 (approx N > 2896 for formula 1+5N+2N^2),
+*  storing the value through a REAL (float32) intermediary loses
+*  precision. This test catches that regression by checking
+*  INT(RWORK(1)) == expected at N values above the threshold.
+*
+*  No large matrices are allocated -- workspace queries return
+*  immediately after storing sizes, so the test runs in microseconds.
+*
+*  =========== END DOCUMENTATION ========
+*
+      PROGRAM TEST_WQ_RWORK
+*
+      IMPLICIT NONE
+*
+*     .. Parameters ..
+      INTEGER            NNVALS
+      PARAMETER          ( NNVALS = 3 )
+*
+*     .. Local Scalars ..
+      INTEGER            INFO, N, LRWEXP, NFAIL, NPASS, I, LRWGOT
+*
+*     .. Local Arrays ..
+*     Minimal dummy arrays for workspace queries (never accessed
+*     by the routines when LWORK=-1).
+      INTEGER            NVALS( NNVALS ), IWORK( 1 )
+      COMPLEX*16         A( 1 ), B( 1 ), AB( 1 ), BB( 1 )
+      COMPLEX*16         AP( 1 ), BP( 1 ), Z( 1 ), WORK( 1 )
+      DOUBLE PRECISION   W( 1 ), RWORK( 1 ), D( 1 ), E( 1 )
+*
+*     .. External Subroutines ..
+      EXTERNAL           ZHEEVD, ZHEGVD, ZHBEVD, ZHPEVD
+      EXTERNAL           ZHPGVD, ZHBGVD, ZSTEDC
+*
+*     Test N values: 1000 (below 2^24 threshold), 3000 and 5000 (above)
+      DATA NVALS / 1000, 3000, 5000 /
+*
+*     .. Executable Statements ..
+*
+      NFAIL = 0
+      NPASS = 0
+*
+      WRITE( *, * ) 'Workspace query precision test for z* RWORK'
+      WRITE( *, * ) '============================================'
+      WRITE( *, * )
+*
+      DO 100 I = 1, NNVALS
+         N = NVALS( I )
+*
+*        Expected LRWMIN for JOBZ='V': 1 + 5*N + 2*N**2
+*        (common to ZHEEVD, ZHEGVD, ZHBEVD, ZHPEVD, ZHPGVD, ZHBGVD)
+*
+         LRWEXP = 1 + 5*N + 2*N*N
+*
+*        ---- ZHEEVD ----
+*
+         INFO = 0
+         CALL ZHEEVD( 'V', 'U', N, A, N, W,
+     $                WORK, -1, RWORK, -1, IWORK, -1, INFO )
+         LRWGOT = INT( RWORK( 1 ) )
+         IF( INFO.EQ.0 .AND. LRWGOT.EQ.LRWEXP ) THEN
+            NPASS = NPASS + 1
+         ELSE
+            NFAIL = NFAIL + 1
+            WRITE( *, 9999 ) 'ZHEEVD ', N, LRWEXP, LRWGOT, INFO
+         END IF
+*
+*        ---- ZHEGVD ----
+*
+         INFO = 0
+         CALL ZHEGVD( 1, 'V', 'U', N, A, N, B, N, W,
+     $                WORK, -1, RWORK, -1, IWORK, -1, INFO )
+         LRWGOT = INT( RWORK( 1 ) )
+         IF( INFO.EQ.0 .AND. LRWGOT.EQ.LRWEXP ) THEN
+            NPASS = NPASS + 1
+         ELSE
+            NFAIL = NFAIL + 1
+            WRITE( *, 9999 ) 'ZHEGVD ', N, LRWEXP, LRWGOT, INFO
+         END IF
+*
+*        ---- ZHBEVD ----
+*        KD=0 (diagonal band matrix), LDAB=1, LDZ=N
+*
+         INFO = 0
+         CALL ZHBEVD( 'V', 'U', N, 0, AB, 1, W, Z, N,
+     $                WORK, -1, RWORK, -1, IWORK, -1, INFO )
+         LRWGOT = INT( RWORK( 1 ) )
+         IF( INFO.EQ.0 .AND. LRWGOT.EQ.LRWEXP ) THEN
+            NPASS = NPASS + 1
+         ELSE
+            NFAIL = NFAIL + 1
+            WRITE( *, 9999 ) 'ZHBEVD ', N, LRWEXP, LRWGOT, INFO
+         END IF
+*
+*        ---- ZHPEVD ----
+*        LDZ=N
+*
+         INFO = 0
+         CALL ZHPEVD( 'V', 'U', N, AP, W, Z, N,
+     $                WORK, -1, RWORK, -1, IWORK, -1, INFO )
+         LRWGOT = INT( RWORK( 1 ) )
+         IF( INFO.EQ.0 .AND. LRWGOT.EQ.LRWEXP ) THEN
+            NPASS = NPASS + 1
+         ELSE
+            NFAIL = NFAIL + 1
+            WRITE( *, 9999 ) 'ZHPEVD ', N, LRWEXP, LRWGOT, INFO
+         END IF
+*
+*        ---- ZHPGVD ----
+*        ITYPE=1, LDZ=N
+*
+         INFO = 0
+         CALL ZHPGVD( 1, 'V', 'U', N, AP, BP, W, Z, N,
+     $                WORK, -1, RWORK, -1, IWORK, -1, INFO )
+         LRWGOT = INT( RWORK( 1 ) )
+         IF( INFO.EQ.0 .AND. LRWGOT.EQ.LRWEXP ) THEN
+            NPASS = NPASS + 1
+         ELSE
+            NFAIL = NFAIL + 1
+            WRITE( *, 9999 ) 'ZHPGVD ', N, LRWEXP, LRWGOT, INFO
+         END IF
+*
+*        ---- ZHBGVD ----
+*        KA=0, KB=0, LDAB=1, LDBB=1, LDZ=N
+*
+         INFO = 0
+         CALL ZHBGVD( 'V', 'U', N, 0, 0, AB, 1, BB, 1,
+     $                W, Z, N,
+     $                WORK, -1, RWORK, -1, IWORK, -1, INFO )
+         LRWGOT = INT( RWORK( 1 ) )
+         IF( INFO.EQ.0 .AND. LRWGOT.EQ.LRWEXP ) THEN
+            NPASS = NPASS + 1
+         ELSE
+            NFAIL = NFAIL + 1
+            WRITE( *, 9999 ) 'ZHBGVD ', N, LRWEXP, LRWGOT, INFO
+         END IF
+*
+*        ---- ZSTEDC (COMPZ='I') ----
+*        Expected: 1 + 4*N + 2*N**2
+*
+         LRWEXP = 1 + 4*N + 2*N*N
+*
+         INFO = 0
+         CALL ZSTEDC( 'I', N, D, E, Z, N,
+     $                WORK, -1, RWORK, -1, IWORK, -1, INFO )
+         LRWGOT = INT( RWORK( 1 ) )
+         IF( INFO.EQ.0 .AND. LRWGOT.EQ.LRWEXP ) THEN
+            NPASS = NPASS + 1
+         ELSE
+            NFAIL = NFAIL + 1
+            WRITE( *, 9999 ) 'ZSTEDC ', N, LRWEXP, LRWGOT, INFO
+         END IF
+*
+  100 CONTINUE
+*
+*     Print summary
+*
+      WRITE( *, * )
+      IF( NFAIL.EQ.0 ) THEN
+         WRITE( *, 9998 ) NPASS
+      ELSE
+         WRITE( *, 9997 ) NFAIL, NFAIL + NPASS
+      END IF
+*
+ 9999 FORMAT( ' FAIL: ', A7, ' N=', I6,
+     $        ' expected=', I12, ' got=', I12, ' INFO=', I4 )
+ 9998 FORMAT( ' All ', I3, ' workspace query tests PASSED' )
+ 9997 FORMAT( ' ', I3, ' of ', I3, ' tests FAILED' )
+*
+      IF( NFAIL.NE.0 ) STOP 1
+*
+      END