diff --git a/CMakeLists.txt b/CMakeLists.txt
index 556cdf06..34d69400 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -38,8 +38,8 @@ elseif ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "GNU")
 endif ()
 
 set(include_dir "${PROJECT_SOURCE_DIR}/include")
-file(GLOB_RECURSE sqlpp_headers ${include_dir}/*.h)
-include_directories(${include_dir})
+file(GLOB_RECURSE sqlpp_headers "${include_dir}/*.h")
+include_directories("${include_dir}")
 add_subdirectory(tests)
 add_subdirectory(test_constraints)
 
diff --git a/test_constraints/CMakeLists.txt b/test_constraints/CMakeLists.txt
index aec592e4..55255498 100644
--- a/test_constraints/CMakeLists.txt
+++ b/test_constraints/CMakeLists.txt
@@ -1,26 +1,26 @@
-include_directories(${CMAKE_SOURCE_DIR}/tests)
+include_directories("${CMAKE_SOURCE_DIR}/tests")
 
 add_custom_target(test_sqlpp_constraints COMMAND true)
 
 function(test_constraint name pattern)
 
 	add_executable(
-		${name}
+		"${name}"
 		EXCLUDE_FROM_ALL
-		${name}.cpp
+		"${name}.cpp"
 		)
 
-	add_custom_command(OUTPUT ${name}.out
-				COMMAND ${CMAKE_MAKE_PROGRAM} ${name} > ${CMAKE_CURRENT_BINARY_DIR}/${name}.out 2>&1  || true
-				COMMAND grep ${pattern} ${CMAKE_CURRENT_BINARY_DIR}/${name}.out > /dev/null
-				DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/${name}.cpp
+	add_custom_command(OUTPUT "${name}.out"
+				COMMAND "${CMAKE_MAKE_PROGRAM}" "${name}" > "${CMAKE_CURRENT_BINARY_DIR}/${name}.out" 2>&1  || true
+				COMMAND grep "${pattern}" "${CMAKE_CURRENT_BINARY_DIR}/${name}.out" > /dev/null
+				DEPENDS "${CMAKE_CURRENT_SOURCE_DIR}/${name}.cpp"
 				COMMENT "${name}"
-				)
+				VERBATIM)
 
-	add_custom_target(test_${name} DEPENDS ${name}.out COMMAND true)
+	add_custom_target("test_${name}" DEPENDS "${name}.out" COMMAND true)
 
 
-	add_dependencies(test_sqlpp_constraints test_${name})
+	add_dependencies(test_sqlpp_constraints "test_${name}")
 
 endfunction(test_constraint)
 
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 6582425b..86462e61 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -1,9 +1,9 @@
 
 macro (build_and_run arg)
 	# Add headers to sources to enable file browsing in IDEs
-	include_directories(${CMAKE_BINARY_DIR}/tests)
-	add_executable(${arg} ${arg}.cpp ${sqlpp_headers} ${CMAKE_CURRENT_LIST_DIR}/Sample.h)
-	add_test(${arg} ${arg})
+	include_directories("${CMAKE_BINARY_DIR}/tests")
+	add_executable("${arg}" "${arg}.cpp" ${sqlpp_headers} "${CMAKE_CURRENT_LIST_DIR}/Sample.h")
+	add_test("${arg}" "${arg}")
 endmacro ()
 
 build_and_run(BooleanExpressionTest)
@@ -21,8 +21,7 @@ build_and_run(ResultTest)
 # if you want to use the generator, you can do something like this:
 #find_package(PythonInterp REQUIRED)
 #add_custom_command(
-#	OUTPUT ${CMAKE_CURRENT_LIST_DIR}/Sample.h 
-#	COMMAND ${PYTHON_EXECUTABLE} ${CMAKE_SOURCE_DIR}/scripts/ddl2cpp ${CMAKE_CURRENT_LIST_DIR}/sample.sql Sample test
-#	DEPENDS ${CMAKE_CURRENT_LIST_DIR}/sample.sql
-#	)
-
+#	OUTPUT "${CMAKE_CURRENT_LIST_DIR}/Sample.h"
+#	COMMAND "${PYTHON_EXECUTABLE}" "${CMAKE_SOURCE_DIR}/scripts/ddl2cpp" "${CMAKE_CURRENT_LIST_DIR}/sample.sql" Sample test
+#	DEPENDS "${CMAKE_CURRENT_LIST_DIR}/sample.sql"
+#	VERBATIM)