diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index f583d571..8a11ef96 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -50,38 +50,38 @@ if (_GLFW_WAYLAND)
     pkg_get_variable(WAYLAND_PROTOCOLS_BASE wayland-protocols pkgdatadir)
 
     macro(wayland_generate protocol_file output_file)
-          add_custom_command(OUTPUT ${output_file}.h
-              COMMAND ${WAYLAND_SCANNER_EXECUTABLE} client-header
-              < ${protocol_file} > ${output_file}.h
-              DEPENDS ${protocol_file})
-          list(APPEND GLFW_WAYLAND_PROTOCOL_SOURCES ${output_file}.h)
+          add_custom_command(OUTPUT "${output_file}.h"
+              COMMAND "${WAYLAND_SCANNER_EXECUTABLE}" client-header
+              < "${protocol_file}" > "${output_file}.h"
+              DEPENDS "${protocol_file}")
+          list(APPEND GLFW_WAYLAND_PROTOCOL_SOURCES "${output_file}.h)"
 
-          add_custom_command(OUTPUT ${output_file}.c
-              COMMAND ${WAYLAND_SCANNER_EXECUTABLE} private-code
-              < ${protocol_file} > ${output_file}.c
-              DEPENDS ${protocol_file})
-          list(APPEND GLFW_WAYLAND_PROTOCOL_SOURCES ${output_file}.c)
+          add_custom_command(OUTPUT "${output_file}.c"
+              COMMAND "${WAYLAND_SCANNER_EXECUTABLE}" private-code
+              < "${protocol_file}" > "${output_file}.c"
+              DEPENDS "${protocol_file}")
+          list(APPEND GLFW_WAYLAND_PROTOCOL_SOURCES "${output_file}.c")
     endmacro()
 
     set(GLFW_WAYLAND_PROTOCOL_SOURCES)
     wayland_generate(
-        ${WAYLAND_PROTOCOLS_BASE}/stable/xdg-shell/xdg-shell.xml
-        ${GLFW_BINARY_DIR}/src/wayland-xdg-shell-client-protocol)
+        "${WAYLAND_PROTOCOLS_BASE}/stable/xdg-shell/xdg-shell.xml"
+        "${GLFW_BINARY_DIR}/src/wayland-xdg-shell-client-protocol")
     wayland_generate(
-        ${WAYLAND_PROTOCOLS_BASE}/unstable/xdg-decoration/xdg-decoration-unstable-v1.xml
-        ${GLFW_BINARY_DIR}/src/wayland-xdg-decoration-client-protocol)
+        "${WAYLAND_PROTOCOLS_BASE}/unstable/xdg-decoration/xdg-decoration-unstable-v1.xml"
+        "${GLFW_BINARY_DIR}/src/wayland-xdg-decoration-client-protocol")
     wayland_generate(
-        ${WAYLAND_PROTOCOLS_BASE}/stable/viewporter/viewporter.xml
-        ${GLFW_BINARY_DIR}/src/wayland-viewporter-client-protocol)
+        "${WAYLAND_PROTOCOLS_BASE}/stable/viewporter/viewporter.xml"
+        "${GLFW_BINARY_DIR}/src/wayland-viewporter-client-protocol")
     wayland_generate(
-        ${WAYLAND_PROTOCOLS_BASE}/unstable/relative-pointer/relative-pointer-unstable-v1.xml
-        ${GLFW_BINARY_DIR}/src/wayland-relative-pointer-unstable-v1-client-protocol)
+        "${WAYLAND_PROTOCOLS_BASE}/unstable/relative-pointer/relative-pointer-unstable-v1.xml"
+        "${GLFW_BINARY_DIR}/src/wayland-relative-pointer-unstable-v1-client-protocol")
     wayland_generate(
-        ${WAYLAND_PROTOCOLS_BASE}/unstable/pointer-constraints/pointer-constraints-unstable-v1.xml
-        ${GLFW_BINARY_DIR}/src/wayland-pointer-constraints-unstable-v1-client-protocol)
+        "${WAYLAND_PROTOCOLS_BASE}/unstable/pointer-constraints/pointer-constraints-unstable-v1.xml"
+        "${GLFW_BINARY_DIR}/src/wayland-pointer-constraints-unstable-v1-client-protocol")
     wayland_generate(
-        ${WAYLAND_PROTOCOLS_BASE}/unstable/idle-inhibit/idle-inhibit-unstable-v1.xml
-        ${GLFW_BINARY_DIR}/src/wayland-idle-inhibit-unstable-v1-client-protocol)
+        "${WAYLAND_PROTOCOLS_BASE}/unstable/idle-inhibit/idle-inhibit-unstable-v1.xml"
+        "${GLFW_BINARY_DIR}/src/wayland-idle-inhibit-unstable-v1-client-protocol")
 
     target_sources(glfw PRIVATE ${GLFW_WAYLAND_PROTOCOL_SOURCES})
 endif()