diff --git a/CMakeLists.txt b/CMakeLists.txt
index 21d88b4f..4e8fcc1e 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -21,6 +21,7 @@ include(GNUInstallDirs)
 
 
 # Fortran
+option (IPHREEQC_ENABLE_MODULE "Enable Fortran module" ON)
 if (STANDALONE_BUILD EQUAL 1)
   if (NOT IPHREEQC_FORTRAN_TESTING)
     if (NOT CMAKE_Fortran_COMPILER OR CMAKE_Fortran_COMPILER STREQUAL "CMAKE_Fortran_COMPILER-NOTFOUND")
@@ -201,20 +202,23 @@ src/phreeqcpp/Utils.h
 # compile Var.c as c++
 SET_SOURCE_FILES_PROPERTIES(src/Var.c PROPERTIES LANGUAGE CXX)
 
-# always include fwrap files
-SET(IPhreeqc_SOURCES
-${IPhreeqc_SOURCES}
-src/fimpl.h
-src/fwrap.cpp
-src/fwrap1.cpp
-src/fwrap2.cpp
-src/fwrap3.cpp
-src/fwrap4.cpp
-src/fwrap5.cpp
-src/fwrap6.cpp      
-src/fwrap7.cpp
-src/fwrap8.cpp      
-)
+# fwrap files
+if (NOT IPHREEQC_ENABLE_MODULE)
+  add_definitions(-DIPHREEQC_NO_FORTRAN_MODULE)
+  SET(IPhreeqc_SOURCES
+  ${IPhreeqc_SOURCES}
+  src/fimpl.h
+  src/fwrap.cpp
+  src/fwrap1.cpp
+  src/fwrap2.cpp
+  src/fwrap3.cpp
+  src/fwrap4.cpp
+  src/fwrap5.cpp
+  src/fwrap6.cpp      
+  src/fwrap7.cpp
+  src/fwrap8.cpp      
+ )
+endif()
 
 # setup include directories
 include_directories("${PROJECT_SOURCE_DIR}")
@@ -240,14 +244,20 @@ add_library(IPhreeqc ${LIB_TYPE} ${IPhreeqc_SOURCES})
 set_target_properties(IPhreeqc PROPERTIES DEBUG_POSTFIX "d")
 
 SET(IPhreeqc_Headers
-${PROJECT_SOURCE_DIR}/src/IPhreeqc.f.inc
-${PROJECT_SOURCE_DIR}/src/IPhreeqc.f90.inc
 ${PROJECT_SOURCE_DIR}/src/IPhreeqc.h
 ${PROJECT_SOURCE_DIR}/src/IPhreeqc.hpp
 ${PROJECT_SOURCE_DIR}/src/IPhreeqcCallbacks.h
 ${PROJECT_SOURCE_DIR}/src/Var.h
 )
 
+if (NOT IPHREEQC_ENABLE_MODULE)
+  SET(IPhreeqc_Headers
+  ${IPhreeqc_Headers}
+  ${PROJECT_SOURCE_DIR}/src/IPhreeqc.f.inc
+  ${PROJECT_SOURCE_DIR}/src/IPhreeqc.f90.inc
+  )
+endif()
+
 
 # Setup references for /CLR
 if (MSVC AND BUILD_SHARED_LIBS AND BUILD_CLR_LIBS)
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index fafe1209..11898cd7 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -85,11 +85,23 @@ if (IPHREEQC_FORTRAN_TESTING)
    
   # source
   SET(test_f90_SOURCES
-    ../src/IPhreeqc_interface.F90
     main.f90
-    test_f90.f90
+    test_f90.F90
   )
   
+  if (IPHREEQC_ENABLE_MODULE)
+    SET(test_f90_SOURCES
+      ${test_f90_SOURCES}
+      ../src/IPhreeqc_interface.F90
+    )
+  endif()
+  
+  # place [*.F[90]] files into "Source Files"
+  source_group("Source Files" FILES "test_f90.F90")
+  if (IPHREEQC_ENABLE_MODULE)
+    source_group("Source Files" FILES "../src/IPhreeqc_interface.F90")
+  endif()
+  
   # test executable
   add_executable(test_f90 ${test_f90_SOURCES})