diff --git a/configure.ac b/configure.ac
index 9780991122e4..b9b30ddee503 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1537,6 +1537,7 @@
         AC_CHECK_LIB([htp], [htp_tx_get_response_headers_raw],AC_DEFINE_UNQUOTED([HAVE_HTP_TX_GET_RESPONSE_HEADERS_RAW],[1],[Found htp_tx_get_response_headers_raw in libhtp]) ,,[-lhtp])
         AC_CHECK_LIB([htp], [htp_decode_query_inplace],AC_DEFINE_UNQUOTED([HAVE_HTP_DECODE_QUERY_INPLACE],[1],[Found htp_decode_query_inplace function in libhtp]) ,,[-lhtp])
         AC_CHECK_LIB([htp], [htp_config_set_response_decompression_layer_limit],AC_DEFINE_UNQUOTED([HAVE_HTP_CONFIG_SET_RESPONSE_DECOMPRESSION_LAYER_LIMIT],[1],[Found htp_config_set_response_decompression_layer_limit function in libhtp]) ,,[-lhtp])
+        AC_CHECK_LIB([htp], [htp_config_set_allow_space_uri],AC_DEFINE_UNQUOTED([HAVE_HTP_CONFIG_SET_ALLOW_SPACE_URI],[1],[Found htp_config_set_allow_space_uri function in libhtp]) ,,[-lhtp])
         AC_EGREP_HEADER(htp_config_set_path_decode_u_encoding, htp/htp.h, AC_DEFINE_UNQUOTED([HAVE_HTP_SET_PATH_DECODE_U_ENCODING],[1],[Found usable htp_config_set_path_decode_u_encoding function in libhtp]) )
         AC_CHECK_LIB([htp], [htp_config_set_lzma_memlimit],AC_DEFINE_UNQUOTED([HAVE_HTP_CONFIG_SET_LZMA_MEMLIMIT],[1],[Found htp_config_set_lzma_memlimit function in libhtp]) ,,[-lhtp])
         AC_CHECK_LIB([htp], [htp_config_set_lzma_layers],AC_DEFINE_UNQUOTED([HAVE_HTP_CONFIG_SET_LZMA_LAYERS],[1],[Found htp_config_set_lzma_layers function in libhtp]) ,,[-lhtp])
@@ -1562,6 +1563,7 @@
             AC_DEFINE_UNQUOTED([HAVE_HTP_DECODE_QUERY_INPLACE],[1],[Assuming htp_decode_query_inplace function in bundled libhtp])
             # enable when libhtp has been updated
             AC_DEFINE_UNQUOTED([HAVE_HTP_CONFIG_SET_RESPONSE_DECOMPRESSION_LAYER_LIMIT],[1],[Assuming htp_config_set_response_decompression_layer_limit function in bundled libhtp])
+            AC_DEFINE_UNQUOTED([HAVE_HTP_CONFIG_SET_ALLOW_SPACE_URI],[1],[Assuming htp_config_set_allow_space_uri function in bundled libhtp])
             AC_DEFINE_UNQUOTED([HAVE_HTP_CONFIG_SET_LZMA_MEMLIMIT],[1],[Assuming htp_config_set_lzma_memlimit function in bundled libhtp])
             AC_DEFINE_UNQUOTED([HAVE_HTP_CONFIG_SET_LZMA_LAYERS],[1],[Assuming htp_config_set_lzma_layers function in bundled libhtp])
             AC_DEFINE_UNQUOTED([HAVE_HTP_CONFIG_SET_COMPRESSION_BOMB_LIMIT],[1],[Assuming htp_config_set_compression_bomb_limit function in bundled libhtp])
diff --git a/doc/userguide/upgrade.rst b/doc/userguide/upgrade.rst
index 9f2df10ef592..18e6e7cfe2c8 100644
--- a/doc/userguide/upgrade.rst
+++ b/doc/userguide/upgrade.rst
@@ -36,6 +36,10 @@ Upgrading 6.0 to 7.0
 Major changes
 ~~~~~~~~~~~~~
 - Upgrade of PCRE1 to PCRE2. See :ref:`pcre-update-v1-to-v2` for more details.
+- Spaces are accepted in HTTP1 URIs instead of in the protocol version
+
+That is `GET /a b HTTP/1.1` gets now URI as `a b` and protocol as `HTTP/1.1` when
+it used to be URI as `a` and protocol as `b HTTP/1.1`
 
 Removals
 ~~~~~~~~
diff --git a/src/app-layer-htp.c b/src/app-layer-htp.c
index fcdd7eba1d9c..5690a02ebb6d 100644
--- a/src/app-layer-htp.c
+++ b/src/app-layer-htp.c
@@ -2449,6 +2449,9 @@ static void HTPConfigSetDefaultsPhase1(HTPCfgRec *cfg_prec)
     htp_config_register_response_complete(cfg_prec->cfg, HTPCallbackResponseComplete);
 
     htp_config_set_parse_request_cookies(cfg_prec->cfg, 0);
+#ifdef HAVE_HTP_CONFIG_SET_ALLOW_SPACE_URI
+    htp_config_set_allow_space_uri(cfg_prec->cfg, 1);
+#endif
 
     /* don't convert + to space by default */
     htp_config_set_plusspace_decode(cfg_prec->cfg, HTP_DECODER_URLENCODED, 0);
diff --git a/src/detect-http-protocol.c b/src/detect-http-protocol.c
index 0f32154ddd2a..6111a2c03970 100644
--- a/src/detect-http-protocol.c
+++ b/src/detect-http-protocol.c
@@ -116,6 +116,26 @@ static InspectionBuffer *GetData(DetectEngineThreadCtx *det_ctx,
     return buffer;
 }
 
+static bool DetectHttpProtocolValidateCallback(const Signature *s, const char **sigerror)
+{
+#ifdef HAVE_HTP_CONFIG_SET_ALLOW_SPACE_URI
+    const SigMatch *sm = s->init_data->smlists[g_buffer_id];
+    for (; sm != NULL; sm = sm->next) {
+        if (sm->type != DETECT_CONTENT)
+            continue;
+        const DetectContentData *cd = (DetectContentData *)sm->ctx;
+        for (size_t i = 0; i < cd->content_len; ++i) {
+            if (cd->content[i] == ' ') {
+                *sigerror = "Invalid http.protocol string containing a space";
+                SCLogWarning(SC_WARN_POOR_RULE, "rule %u: %s", s->id, *sigerror);
+                return false;
+            }
+        }
+    }
+#endif
+    return true;
+}
+
 /**
  * \brief Registers the keyword handlers for the "http.protocol" keyword.
  */
@@ -139,6 +159,7 @@ void DetectHttpProtocolRegister(void)
 
     DetectBufferTypeSetDescriptionByName(BUFFER_NAME,
             BUFFER_DESC);
+    DetectBufferTypeRegisterValidateCallback(BUFFER_NAME, DetectHttpProtocolValidateCallback);
 
     g_buffer_id = DetectBufferTypeGetByName(BUFFER_NAME);
 }