diff --git a/src/vim9execute.c b/src/vim9execute.c
index c0a4874..6b8cd07 100644
--- a/src/vim9execute.c
+++ b/src/vim9execute.c
@@ -323,6 +323,8 @@
     else
 	ectx->ec_outer = NULL;
 
+    ++ufunc->uf_calls;
+
     // Set execution state to the start of the called function.
     ectx->ec_dfunc_idx = cdf_idx;
     ectx->ec_instr = INSTRUCTIONS(dfunc);
@@ -556,6 +558,9 @@
 	}
     }
 #endif
+    // TODO: when is it safe to delete the function when it is no longer used?
+    --dfunc->df_ufunc->uf_calls;
+
     // execution context goes one level up
     entry = estack_pop();
     if (entry != NULL)
@@ -1334,7 +1339,7 @@
 	    ++ectx.ec_stack.ga_len;
 	}
     if (ufunc->uf_va_name != NULL)
-	    ++ectx.ec_stack.ga_len;
+	++ectx.ec_stack.ga_len;
 
     // Frame pointer points to just after arguments.
     ectx.ec_frame_idx = ectx.ec_stack.ga_len;
@@ -1407,6 +1412,9 @@
     // Do turn errors into exceptions.
     suppress_errthrow = FALSE;
 
+    // Do not delete the function while executing it.
+    ++ufunc->uf_calls;
+
     // When ":silent!" was used before calling then we still abort the
     // function.  If ":silent!" is used in the function then we don't.
     emsg_silent_def = emsg_silent;
@@ -3838,6 +3846,9 @@
     estack_pop();
     current_sctx = save_current_sctx;
 
+    // TODO: when is it safe to delete the function if it is no longer used?
+    --ufunc->uf_calls;
+
     if (*msg_list != NULL && saved_msg_list != NULL)
     {
 	msglist_T **plist = saved_msg_list;