diff --git a/src/apps/terminal/Shell.cpp b/src/apps/terminal/Shell.cpp
index 67442bd2e5..5f33669a40 100644
--- a/src/apps/terminal/Shell.cpp
+++ b/src/apps/terminal/Shell.cpp
@@ -58,10 +58,14 @@
 /*
  * Set environment variable.
  */
-#if defined(HAIKU_TARGET_PLATFORM_BEOS) || defined(HAIKU_TARGET_PLATFORM_LIBBE_TEST)
+#if defined(HAIKU_TARGET_PLATFORM_BEOS) || \
+	defined(HAIKU_TARGET_PLATFORM_BONE) || \
+	defined(HAIKU_TARGET_PLATFORM_LIBBE_TEST)
 
 extern char **environ;
 
+static int setenv(const char *var, const char *value, bool overwrite);
+
 static int
 setenv(const char *var, const char *value, bool overwrite)
 {