diff --git a/blas/testing/CMakeLists.txt b/blas/testing/CMakeLists.txt
index f0ee6a487..8b8ff44fd 100644
--- a/blas/testing/CMakeLists.txt
+++ b/blas/testing/CMakeLists.txt
@@ -48,5 +48,13 @@ ei_add_blas_test(zblat3)
 # add_custom_target(level1)
 # add_dependencies(level1 sblat1)
 
+# Workaround for gfortran -O3 bug.  The optimization
+# introduces a bug in the calculation of the norm of the error
+# in the complex case.
+if(CMAKE_Fortran_COMPILER_ID MATCHES "GNU")
+  target_compile_options(cblat3 PRIVATE "-O0")
+  target_compile_options(zblat3 PRIVATE "-O0")
+endif()
+
 endif()