diff --git a/include/extern.h b/include/extern.h
index d2d020ffe..1ff918be4 100644
--- a/include/extern.h
+++ b/include/extern.h
@@ -3757,6 +3757,7 @@ extern void flip_worm_segs_horizontal(struct monst *, int, int) NONNULLARG1;
 
 /* ### worn.c ### */
 
+extern void recalc_telepat_range(void);
 extern void setworn(struct obj *, long) NO_NNARGS; /* has tests for obj */
 extern void setnotworn(struct obj *) NO_NNARGS; /* has tests for obj */
 extern void allunworn(void);
diff --git a/src/artifact.c b/src/artifact.c
index 54c3e8066..40b46a44d 100644
--- a/src/artifact.c
+++ b/src/artifact.c
@@ -711,6 +711,7 @@ set_artifact_intrinsic(struct obj *otmp, boolean on, long wp_mask)
             ETelepat |= wp_mask;
         else
             ETelepat &= ~wp_mask;
+        recalc_telepat_range();
         see_monsters();
     }
     if (spfx & SPFX_STLTH) {
diff --git a/src/worn.c b/src/worn.c
index 3ab06ac2b..87ed95ffd 100644
--- a/src/worn.c
+++ b/src/worn.c
@@ -5,7 +5,6 @@
 
 #include "hack.h"
 
-staticfn void recalc_telepat_range(void);
 staticfn void m_lose_armor(struct monst *, struct obj *, boolean) NONNULLPTRS;
 staticfn void clear_bypass(struct obj *) NO_NNARGS;
 staticfn void m_dowear_type(struct monst *, long, boolean, boolean) NONNULLARG1;
@@ -46,7 +45,7 @@ static const struct worn {
    has no significant effect on their use of w_blocks() */
 
 /* calc the range of hero's unblind telepathy */
-staticfn void
+void
 recalc_telepat_range(void)
 {
     const struct worn *wp;
@@ -58,6 +57,10 @@ recalc_telepat_range(void)
         if (oobj && objects[oobj->otyp].oc_oprop == TELEPAT)
             nobjs++;
     }
+    /* count all artifacts with SPFX_ESP as one */
+    if (ETelepat & W_ART)
+        nobjs++;
+
     if (nobjs)
         u.unblind_telepat_range = (BOLT_LIM * BOLT_LIM) * nobjs;
     else