diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 8d1110c9..1099161f 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -118,7 +118,7 @@ endif()
 if (USE_NETCDF3)
   shell_test(run_wgrib2_netcdf3_tests)
 endif()
-if (USE_IPOLATES=1)
+if (USE_IPOLATES EQUAL 1)
   shell_test(run_ipolates_tests)
 endif()
 if (USE_AEC)