Index: src/expr.c
==================================================================
--- src/expr.c
+++ src/expr.c
@@ -2514,10 +2514,13 @@
       if( pX->pLeft->iColumn<0 && !ExprHasProperty(pX, EP_xIsSelect) ){
         eType = IN_INDEX_ROWID;
       }
     }else if( prRhsHasNull ){
       *prRhsHasNull = rMayHaveNull = ++pParse->nMem;
+    }
+    if( ExprHasProperty(pX, EP_xIsSelect) ){
+      pX->x.pSelect->selFlags |= SF_RhsOfIN;
     }
     sqlite3CodeSubselect(pParse, pX, rMayHaveNull, eType==IN_INDEX_ROWID);
     pParse->nQueryLoop = savedNQueryLoop;
   }else{
     pX->iTable = iTab;

Index: src/select.c
==================================================================
--- src/select.c
+++ src/select.c
@@ -5877,18 +5877,19 @@
 
     /* Generate code to implement the subquery
     **
     ** The subquery is implemented as a co-routine if the subquery is
     ** guaranteed to be the outer loop (so that it does not need to be
-    ** computed more than once)
+    ** computed more than once). (1)
     **
-    ** TODO: Are there other reasons beside (1) to use a co-routine
-    ** implementation?
+    ** Avoid using a co-routines to compute any SELECT that occurs in
+    ** the RHS of an IN operator, as they can be used multiple times. (2)
     */
     if( i==0
      && (pTabList->nSrc==1
             || (pTabList->a[1].fg.jointype&(JT_LEFT|JT_CROSS))!=0)  /* (1) */
+     && (p->selFlags & SF_RhsOfIN)==0                               /* (2) */
     ){
       /* Implement a co-routine that will return a single row of the result
       ** set on each invocation.
       */
       int addrTop = sqlite3VdbeCurrentAddr(v)+1;

Index: src/sqliteInt.h
==================================================================
--- src/sqliteInt.h
+++ src/sqliteInt.h
@@ -2862,10 +2862,11 @@
 #define SF_FixedLimit     0x04000  /* nSelectRow set by a constant LIMIT */
 #define SF_MaybeConvert   0x08000  /* Need convertCompoundSelectToSubquery() */
 #define SF_Converted      0x10000  /* By convertCompoundSelectToSubquery() */
 #define SF_IncludeHidden  0x20000  /* Include hidden columns in output */
 #define SF_ComplexResult  0x40000  /* Result contains subquery or function */
+#define SF_RhsOfIN        0x80000  /* Result uses as the RHS of IN operator */
 
 /*
 ** The results of a SELECT can be distributed in several ways, as defined
 ** by one of the following macros.  The "SRT" prefix means "SELECT Result
 ** Type".