diff --git a/src/mcxlab.cpp b/src/mcxlab.cpp
index 94d2697c..d3fb4199 100644
--- a/src/mcxlab.cpp
+++ b/src/mcxlab.cpp
@@ -654,8 +654,8 @@ void mcx_set_field(const mxArray* root, const mxArray* item, int idx, Config* cf
     } else if (strcmp(name, "srcparam1") == 0) {
         arraydim = mxGetDimensions(item);
 
-        if (arraydim[0] == 0 || arraydim[1] != 4) {
-            mexErrMsgTxt("the 'srcparam1' field must have 4 columns");
+        if (arraydim[0] == 0 || (arraydim[1] != 3 && arraydim[1] != 4)) {
+            mexErrMsgTxt("the 'srcparam1' field must have 3-4 columns");
         }
 
         double* val = mxGetPr(item);
@@ -689,8 +689,8 @@ void mcx_set_field(const mxArray* root, const mxArray* item, int idx, Config* cf
     } else if (strcmp(name, "srcparam2") == 0) {
         arraydim = mxGetDimensions(item);
 
-        if (arraydim[0] == 0 || arraydim[1] != 4) {
-            mexErrMsgTxt("the 'srcparam2' field must have 4 columns");
+        if (arraydim[0] == 0 || (arraydim[1] != 3 && arraydim[1] != 4)) {
+            mexErrMsgTxt("the 'srcparam2' field must have 3-4 columns");
         }
 
         double* val = mxGetPr(item);
diff --git a/src/pmcx.cpp b/src/pmcx.cpp
index b842fa89..3b99c00a 100644
--- a/src/pmcx.cpp
+++ b/src/pmcx.cpp
@@ -553,8 +553,8 @@ void parse_config(const py::dict& user_cfg, Config& mcx_config) {
             arraydim[1] = buffer_info.shape.at(1);
         }
 
-        if (arraydim[0] == 0 || arraydim[1] != 4) {
-            throw py::value_error("the 'srcparam1' field must have 4 columns");
+        if (arraydim[0] == 0 || (arraydim[1] != 3 && arraydim[1] != 4)) {
+            throw py::value_error("the 'srcparam1' field must have 3-4 columns");
         }
 
         auto val = static_cast<float*>(buffer_info.ptr);
@@ -600,8 +600,8 @@ void parse_config(const py::dict& user_cfg, Config& mcx_config) {
             arraydim[1] = buffer_info.shape.at(1);
         }
 
-        if (arraydim[0] == 0 || arraydim[1] != 4) {
-            throw py::value_error("the 'srcparam2' field must have 4 columns");
+        if (arraydim[0] == 0 || (arraydim[1] != 3 && arraydim[1] != 4)) {
+            throw py::value_error("the 'srcparam2' field must have 3-4 columns");
         }
 
         auto val = static_cast<float*>(buffer_info.ptr);