diff --git a/Dockerfile b/Dockerfile
index 2f429a3..2d9b28b 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -33,6 +33,12 @@
 
 COPY . .
 
+# Session::Token, pulled in by Mojolicious::Plugin::Util::RandomString, declares
+# the functions of its bundled isaac implementation without prototypes, which
+# gcc rejects since it defaults to C23. Build this one with C17, the rest of the
+# dependencies compile with the defaults.
+RUN PERL_MM_OPT="CCFLAGS=-std=gnu17" cpm install -g Session::Token
+
 # Install dependencies. Devel::CheckLib, which Makefile.PL needs to find
 # libcollocatordb, comes bundled in inc/
 RUN cpm install -g https://github.com/Akron/Mojolicious-Plugin-Localize.git && \