diff --git a/icu4c/source/tools/gennorm/gennorm.8.in b/icu4c/source/tools/gennorm/gennorm.8.in
index 4c66357ffa0..d4b1dc4feb9 100644
--- a/icu4c/source/tools/gennorm/gennorm.8.in
+++ b/icu4c/source/tools/gennorm/gennorm.8.in
@@ -70,6 +70,13 @@ Print help about usage and exit.
 .BR \-v\fP, \fB\-\-verbose
 Display extra informative messages during execution.
 .TP
+.BI "\-u\fP, \fB\-\-unicode" " version"
+Specify which
+.I  version
+of Unicode the Unicode Character Database refers to.
+Defaults to
+.BR  3.0.0 .
+.TP
 .BI "\-c\fP, \fB\-\-copyright"
 Include a copyright notice into the binary data.
 .TP
diff --git a/icu4c/source/tools/genprops/genprops.8.in b/icu4c/source/tools/genprops/genprops.8.in
index 7c5a9b6ec3e..b682974cad4 100644
--- a/icu4c/source/tools/genprops/genprops.8.in
+++ b/icu4c/source/tools/genprops/genprops.8.in
@@ -70,6 +70,13 @@ Print help about usage and exit.
 .BR \-v\fP, \fB\-\-verbose
 Display extra informative messages during execution.
 .TP
+.BI "\-u\fP, \fB\-\-unicode" " version"
+Specify which
+.I version
+of Unicode the Unicode Character Database refers to.
+Defaults to
+.BR 3.0.0 .
+.TP
 .BI "\-c\fP, \fB\-\-copyright"
 Include a copyright notice into the binary data.
 .TP