diff --git a/Tests/Preprocess/CMakeLists.txt b/Tests/Preprocess/CMakeLists.txt
index 3187c36a0..2401d59b6 100644
--- a/Tests/Preprocess/CMakeLists.txt
+++ b/Tests/Preprocess/CMakeLists.txt
@@ -178,7 +178,7 @@ set(EXPR "x*y+!(x==(y+1*2))*f(x${EXPR_OP1}2)")
 
 if(NOT WATCOM)
   # Watcom does not support - or / because it parses them as options.
-  set(EXPR "${EXPR}+y/x-x")
+  set(EXPR "${EXPR} + y/x-x")
 endif(NOT WATCOM)
 
 #-----------------------------------------------------------------------------