diff --git a/doc/7-systems/opl.md b/doc/7-systems/opl.md
index ac82ded0e..ecc9b4755 100644
--- a/doc/7-systems/opl.md
+++ b/doc/7-systems/opl.md
@@ -81,4 +81,4 @@ afterwards everyone moved to Windows and software mixed PCM streaming...
 
 # info
 
-this chip uses the [FM (OPL)](../4-instrument/fm-opl.md) instrument editor.
+this chip uses the [FM (OPL)](../4-instrument/fmopl.md) instrument editor.
diff --git a/doc/7-systems/opll.md b/doc/7-systems/opll.md
index f32f1eefc..91a3ac6ac 100644
--- a/doc/7-systems/opll.md
+++ b/doc/7-systems/opll.md
@@ -66,7 +66,7 @@ the YM2413 is equipped with the following features:
 
 # info
 
-this chip uses the [FM (OPLL)](../4-instrument/fm-opll.md) instrument editor.
+this chip uses the [FM (OPLL)](../4-instrument/fmopll.md) instrument editor.
 
 ## chip options
 
diff --git a/doc/7-systems/opz.md b/doc/7-systems/opz.md
index c4b0413a9..d7a1071cb 100644
--- a/doc/7-systems/opz.md
+++ b/doc/7-systems/opz.md
@@ -116,4 +116,4 @@ no plans have been made for TX81Z MIDI passthrough, because:
 
 # info
 
-this chip uses the [FM (OPZ)](../4-instrument/opz.md) instrument editor.
+this chip uses the [FM (OPZ)](../4-instrument/fm.md) instrument editor.