diff --git a/docs/style_guide.md b/docs/style_guide.md
index 09f7261..8c27a8c 100644
--- a/docs/style_guide.md
+++ b/docs/style_guide.md
@@ -191,7 +191,7 @@
   * Source sets can have no sources, while static libraries will give strange
     platform-specific errors if they have no sources. If a target has only
     headers (for include checking purposes) or conditionally has no sources on
-    sone platforms, use a source set.
+    some platforms, use a source set.
 
   * In cases where a lot of the symbols are not needed for a particular link
     (this especially happens when linking test binaries), putting that code in