diff --git a/cmake/generate_emoji.cmake b/cmake/generate_emoji.cmake
index 50268df..0c35ec0 100644
--- a/cmake/generate_emoji.cmake
+++ b/cmake/generate_emoji.cmake
@@ -8,10 +8,16 @@ function(generate_emoji target_name suggestions_json)
         ${gen_dst}/emoji.h
         ${gen_dst}/emoji_suggestions_data.cpp
         ${gen_dst}/emoji_suggestions_data.h
+        ${gen_dst}/emoji.timestamp
     )
     add_custom_command(
     OUTPUT
-        ${generated_files}
+        ${gen_dst}/emoji.timestamp
+    BYPRODUCTS
+        ${gen_dst}/emoji.cpp
+        ${gen_dst}/emoji.h
+        ${gen_dst}/emoji_suggestions_data.cpp
+        ${gen_dst}/emoji_suggestions_data.h
     COMMAND
         codegen_emoji
         -o${gen_dst}
diff --git a/cmake/generate_palette.cmake b/cmake/generate_palette.cmake
index d9e8fdb..e22dc48 100644
--- a/cmake/generate_palette.cmake
+++ b/cmake/generate_palette.cmake
@@ -6,10 +6,14 @@ function(generate_palette target_name palette_file)
     set(generated_files
         ${gen_dst}/styles/palette.cpp
         ${gen_dst}/styles/palette.h
+        ${gen_dst}/styles/palette.timestamp
     )
     add_custom_command(
     OUTPUT
-        ${generated_files}
+        ${gen_dst}/styles/palette.timestamp
+    BYPRODUCTS
+        ${gen_dst}/styles/palette.cpp
+        ${gen_dst}/styles/palette.h
     COMMAND
         codegen_style
         -I${gen_dst}
diff --git a/cmake/generate_styles.cmake b/cmake/generate_styles.cmake
index c4767c5..5574655 100644
--- a/cmake/generate_styles.cmake
+++ b/cmake/generate_styles.cmake
@@ -14,11 +14,15 @@ function(generate_styles target_name src_loc style_files dependent_style_files)
         set(generated_files
             ${gen_dst}/styles/style_${file_name}.cpp
             ${gen_dst}/styles/style_${file_name}.h
+            ${gen_dst}/styles/style_${file_name}.timestamp
         )
         list(APPEND full_generated_files ${generated_files})
         add_custom_command(
         OUTPUT
-            ${generated_files}
+            ${gen_dst}/styles/style_${file_name}.timestamp
+        BYPRODUCTS
+            ${gen_dst}/styles/style_${file_name}.cpp
+            ${gen_dst}/styles/style_${file_name}.h
         COMMAND
             codegen_style
             -I${src_loc}