diff --git a/src/command_manager.cc b/src/command_manager.cc
index ac3a5a20..4338e11e 100644
--- a/src/command_manager.cc
+++ b/src/command_manager.cc
@@ -76,11 +76,6 @@ bool is_command_separator(char c)
     return c == ';' or c == '\n';
 }
 
-bool is_horizontal_blank(char c)
-{
-    return c == ' ' or c == '\t';
-}
-
 struct unterminated_string : parse_error
 {
     unterminated_string(const String& open, const String& close, int nest = 0)
diff --git a/src/unicode.hh b/src/unicode.hh
index db2d1e88..ce7e9be2 100644
--- a/src/unicode.hh
+++ b/src/unicode.hh
@@ -24,6 +24,11 @@ inline bool is_blank(Codepoint c)
     return c == ' ' or c == '\t';
 }
 
+inline bool is_horizontal_blank(Codepoint c)
+{
+    return c == ' ' or c == '\t';
+}
+
 }
 
 #endif // unicode_hh_INCLUDED