diff --git a/unittest/fortran/CMakeLists.txt b/unittest/fortran/CMakeLists.txt
index f6c3cd004a..cec38ae55c 100644
--- a/unittest/fortran/CMakeLists.txt
+++ b/unittest/fortran/CMakeLists.txt
@@ -87,7 +87,7 @@ if(CMAKE_Fortran_COMPILER)
   add_test(NAME FortranNeighlist COMMAND test_fortran_neighlist)
 
   # gfortran from GCC 9 on ubuntu has an ICE compiling this test.
-  if ((CMAKE_Fortran_COMPILER_ID STREQUAL "GNU") AND (CMAKE_Fortran_COMPILER_VERSION VERSION_GREATER 9.0))
+  if ((CMAKE_Fortran_COMPILER_ID STREQUAL "GNU") AND (CMAKE_Fortran_COMPILER_VERSION VERSION_GREATER 9.9))
     add_executable(test_fortran_fixexternal wrap_fixexternal.cpp test_fortran_fixexternal.f90)
     target_link_libraries(test_fortran_fixexternal PRIVATE flammps lammps GTest::GMockMain)
     add_test(NAME FortranFixExternal COMMAND test_fortran_fixexternal)