diff --git a/src/rinterface.c b/src/rinterface.c
index d6c93c93b63..f74588cd392 100644
--- a/src/rinterface.c
+++ b/src/rinterface.c
@@ -5323,7 +5323,7 @@ SEXP R_igraph_pagerank(SEXP graph, SEXP algo, SEXP vids, SEXP directed, SEXP dam
   igraph_real_t c_damping;
   igraph_vector_t c_weights;
   igraph_arpack_options_t c_options1;
-  void* c_options;
+  void* c_options = NULL;
   SEXP vector;
   SEXP value;
 
@@ -5346,8 +5346,6 @@ SEXP R_igraph_pagerank(SEXP graph, SEXP algo, SEXP vids, SEXP directed, SEXP dam
     if (c_algo == IGRAPH_PAGERANK_ALGO_ARPACK) {
       Rz_SEXP_to_igraph_arpack_options(options, &c_options1);
       c_options = &c_options1;
-    } else {
-      c_options = NULL;
     }
   }
                                         /* Call igraph */
@@ -5396,7 +5394,7 @@ SEXP R_igraph_personalized_pagerank(SEXP graph, SEXP algo, SEXP vids, SEXP direc
   igraph_vector_t c_personalized;
   igraph_vector_t c_weights;
   igraph_arpack_options_t c_options1;
-  void* c_options;
+  void* c_options = NULL;
   SEXP vector;
   SEXP value;
 
@@ -5422,8 +5420,6 @@ SEXP R_igraph_personalized_pagerank(SEXP graph, SEXP algo, SEXP vids, SEXP direc
     if (c_algo == IGRAPH_PAGERANK_ALGO_ARPACK) {
       Rz_SEXP_to_igraph_arpack_options(options, &c_options1);
       c_options = &c_options1;
-    } else {
-      c_options = NULL;
     }
   }
                                         /* Call igraph */
@@ -5472,7 +5468,7 @@ SEXP R_igraph_personalized_pagerank_vs(SEXP graph, SEXP algo, SEXP vids, SEXP di
   igraph_vs_t c_reset_vids;
   igraph_vector_t c_weights;
   igraph_arpack_options_t c_options1;
-  void* c_options;
+  void* c_options = NULL;
   SEXP vector;
   SEXP value;
 
@@ -5497,8 +5493,6 @@ SEXP R_igraph_personalized_pagerank_vs(SEXP graph, SEXP algo, SEXP vids, SEXP di
     if (c_algo == IGRAPH_PAGERANK_ALGO_ARPACK) {
       Rz_SEXP_to_igraph_arpack_options(options, &c_options1);
       c_options = &c_options1;
-    } else {
-      c_options = NULL;
     }
   }
                                         /* Call igraph */
diff --git a/tools/stimulus/types-RC.yaml b/tools/stimulus/types-RC.yaml
index 7c362dba585..3d1ada36ec9 100644
--- a/tools/stimulus/types-RC.yaml
+++ b/tools/stimulus/types-RC.yaml
@@ -995,16 +995,20 @@ SIR_LIST:
             IGRAPH_FINALLY_CLEAN(1);
 
 PAGERANKOPT:
-    CTYPE: |-
+    CTYPE: void*
+    # The argument is optional,
+    # so the code generator wraps the input conversion into `if (!Rf_isNull(...))`.
+    # The pointer is passed on to igraph unconditionally,
+    # therefore it must be initialized here
+    # to stay well-defined on the path where the conversion is skipped.
+    CDECL: |-
       igraph_arpack_options_t %C%1;
-      void*
+      void* %C% = NULL;
     INCONV:
         INOUT: |-
           if (%C1% == IGRAPH_PAGERANK_ALGO_ARPACK) {
             Rz_SEXP_to_igraph_arpack_options(%I%, &%C%1);
             %C% = &%C%1;
-          } else {
-            %C% = NULL;
           }
     OUTCONV:
         INOUT: |-