diff --git a/ChangeLog.d/bugfix_3794.txt b/ChangeLog.d/bugfix_3794.txt
new file mode 100644
index 0000000000..a483ea76ae
--- /dev/null
+++ b/ChangeLog.d/bugfix_3794.txt
@@ -0,0 +1,4 @@
+Bugfix
+  * Fix handling of EOF against 0xff bytes and on platforms with
+    unsigned chars.  Fixes a build failure on platforms where char is
+    unsigned.  Fixes #3794.
diff --git a/programs/ssl/ssl_context_info.c b/programs/ssl/ssl_context_info.c
index df8819a804..d109c1e6f7 100644
--- a/programs/ssl/ssl_context_info.c
+++ b/programs/ssl/ssl_context_info.c
@@ -377,13 +377,13 @@ size_t read_next_b64_code( uint8_t **b64, size_t *max_len )
     int valid_balance = 0;  /* balance between valid and invalid characters */
     size_t len = 0;
     char pad = 0;
-    char c = 0;
+    int c = 0;
 
     while( EOF != c )
     {
         char c_valid = 0;
 
-        c = (char) fgetc( b64_file );
+        c = fgetc( b64_file );
 
         if( pad > 0 )
         {
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index cc6866309f..7d85adb29f 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -166,6 +166,7 @@ if (NOT ${CMAKE_CURRENT_BINARY_DIR} STREQUAL ${CMAKE_CURRENT_SOURCE_DIR})
         link_to_source(seedfile)
     endif()
     link_to_source(compat.sh)
+    link_to_source(context-info.sh)
     link_to_source(data_files)
     link_to_source(scripts)
     link_to_source(ssl-opt.sh)
diff --git a/tests/context-info.sh b/tests/context-info.sh
index 150584b5db..68614ff408 100755
--- a/tests/context-info.sh
+++ b/tests/context-info.sh
@@ -430,6 +430,11 @@ run_test "Binary file instead of text file" \
          -u "Too many bad symbols detected. File check aborted" \
          -n "Deserializing"
 
+run_test "Decoder continues past 0xff character" \
+         "def_b64_ff.bin" \
+         -n "No valid base64" \
+         -u "ciphersuite.* TLS-"
+
 
 # End of tests
 
diff --git a/tests/data_files/base64/def_b64_ff.bin b/tests/data_files/base64/def_b64_ff.bin
new file mode 100644
index 0000000000..66aa8271c7
--- /dev/null
+++ b/tests/data_files/base64/def_b64_ff.bin
@@ -0,0 +1,5 @@
+// Ensure that the b64 parser continues after encountering a 0xFF
+// character.  Note that this byte is invalid UTF-8, making this
+// entire file invalid UTF-8.  Use care when editing.
+// -> ÿ <-
+AhUAAH8AAA4AAABtAAAAAF6HQx3MqAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAACG2QbHbUj8eGpdx5KVIebiwk0jvRj9/3m6BOSzpA7qBXeEunhqr3D11NE7ciGjeHMAAACAAAAAAAAAAAAAAAAAAV6HQx248L77RH0Z973tSYNQ8zBsz861CZG5/T09TJz3XodDHe/iJ+cgXb5An3zTdnTBtw3EWAb68T+gCE33GN8AAAAAAAAAAAAAAAEAAAAAAAAAAwAAAQAAAAAAAgAAAA==