diff --git a/CMakeLists.txt b/CMakeLists.txt
index b76673863..7768e1961 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -299,6 +299,11 @@ set(devilutionx_SRCS
   Packaging/resources/CharisSILB.ttf
   Packaging/windows/devilutionx.rc)
 
+if(USE_SDL1)
+  list(APPEND devilutionx_SRCS
+    SourceS/sdl2_to_1_2_backports.cpp)
+endif()
+
 if(NOT NONET)
   list(APPEND devilutionx_SRCS
     SourceX/dvlnet/tcp_client.cpp
diff --git a/SourceS/sdl2_to_1_2_backports.cpp b/SourceS/sdl2_to_1_2_backports.cpp
new file mode 100644
index 000000000..4783c1f5b
--- /dev/null
+++ b/SourceS/sdl2_to_1_2_backports.cpp
@@ -0,0 +1,3 @@
+#include "sdl2_to_1_2_backports.h"
+
+SDL_bool SDLBackport_IsTextInputActive = SDL_FALSE;
diff --git a/SourceS/sdl2_to_1_2_backports.h b/SourceS/sdl2_to_1_2_backports.h
index 5a8b59f3c..50a87a2a6 100644
--- a/SourceS/sdl2_to_1_2_backports.h
+++ b/SourceS/sdl2_to_1_2_backports.h
@@ -59,7 +59,7 @@ inline void SDL_Log(const char *fmt, ...)
 	puts("");
 }
 
-static SDL_bool SDLBackport_IsTextInputActive = SDL_FALSE;
+extern SDL_bool SDLBackport_IsTextInputActive;
 
 inline SDL_bool SDL_IsTextInputActive()
 {