diff --git a/usrguide/referenceguide/6-compiling_ttcn3_and_asn1_modules.adoc b/usrguide/referenceguide/6-compiling_ttcn3_and_asn1_modules.adoc
index dbb2b1ba32a5147d09f3d328b1ddced6ce23a8b4..47ee1d286e018c8b672637f2b8289460cd446d18 100644
--- a/usrguide/referenceguide/6-compiling_ttcn3_and_asn1_modules.adoc
+++ b/usrguide/referenceguide/6-compiling_ttcn3_and_asn1_modules.adoc
@@ -401,7 +401,7 @@ Create the makefile with library as the default target. The name of the generate
 
 * `-m`
 +
-Always use `makedepend` for dependencies. By default, for makefiles used by GNU `make`, the compiler (usually GCC) is used to generate dependency information in an incremental fashion. This switch reverts to the process for generic make tools, which uses the `makedepend` tool.
+Always use `makedepend` for dependencies. By default, for makefiles used by GNU `make`, the compiler (usually GCC) is used to generate dependency information in an incremental fashion. This switch reverts to the process for generic make tools, which use the `makedepend` tool. This switch has no effect if switch `-g` (GNU make) is not set.
 
 * `-M`
 +