diff --git a/src/solver/CMakeLists.txt b/src/solver/CMakeLists.txt
index 453c6c63..7791e1ea 100644
--- a/src/solver/CMakeLists.txt
+++ b/src/solver/CMakeLists.txt
@@ -101,9 +101,9 @@ file(COPY ${CMAKE_CURRENT_BINARY_DIR}/toolkit_export.h
 
 # add library directory to rpath incase omp bundled
 if(APPLE)
-    set(LIB_ROOT, "@loader_path")
+    set(LIB_ROOT "@loader_path")
 else()
-    set(LIB_ROOT, "$ORIGIN")
+    set(LIB_ROOT "$ORIGIN")
 endif()
 
 set_target_properties(swmm5