diff --git a/source/blender/blenkernel/intern/particle_system.c b/source/blender/blenkernel/intern/particle_system.c
index 5112fb08fe6..f06ef221795 100644
--- a/source/blender/blenkernel/intern/particle_system.c
+++ b/source/blender/blenkernel/intern/particle_system.c
@@ -4814,9 +4814,20 @@ static void system_step(Object *ob, ParticleSystem *psys, ParticleSystemModifier
 			pa->flag &= ~PARS_NO_DISP;
 	}
 
-	/* ok now we're all set so let's go */
-	if(psys->totpart)
-		dynamics_step(ob,psys,psmd,cfra,vg_vel,vg_tan,vg_rot,vg_size);
+	if(psys->totpart) {
+		int dframe, totframesback = 0;
+
+		/* handle negative frame start at the first frame by doing
+		 * all the steps before the first frame */
+		if(framenr == startframe && part->sta < startframe)
+			totframesback = (startframe - (int)part->sta);
+
+		for(dframe=-totframesback; dframe<=0; dframe++) {
+			/* ok now we're all set so let's go */
+			dynamics_step(ob,psys,psmd,cfra+dframe,vg_vel,vg_tan,vg_rot,vg_size);
+			psys->cfra = cfra+dframe;
+		}
+	}
 	
 	cache->simframe= framenr;
 	cache->flag |= PTCACHE_SIMULATION_VALID;
diff --git a/source/blender/src/buttons_object.c b/source/blender/src/buttons_object.c
index 52261f7d3fb..ba409723784 100644
--- a/source/blender/src/buttons_object.c
+++ b/source/blender/src/buttons_object.c
@@ -4832,7 +4832,7 @@ static void object_panel_particle_system(Object *ob)
 		uiDefButS(block, NUM, B_PART_RECALC, "Segments:",	butx,(buty-=buth),butw,buth, &part->hair_step, 2.0, 50.0, 0, 0, "Amount of hair segments");
 	}
 	else {
-		uiDefButF(block, NUM, B_PART_INIT, "Sta:",		butx,(buty-=buth),butw,buth, &part->sta, 1.0, part->end, 100, 1, "Frame # to start emitting particles");
+		uiDefButF(block, NUM, B_PART_INIT, "Sta:",		butx,(buty-=buth),butw,buth, &part->sta, -MAXFRAMEF, part->end, 100, 1, "Frame # to start emitting particles");
 		uiDefButF(block, NUM, B_PART_INIT, "End:",		butx,(buty-=buth),butw,buth, &part->end, part->sta, MAXFRAMEF, 100, 1, "Frame # to stop emitting particles");
 	}